The use of wireless local area networks (LANs) is growing at an ever-increasing rate. In addition, the data rates of such wireless LANs are continually rising. The algorithms used to manage and optimize wireless LAN receiver performance rely on having an accurate measurement of the strength of the received radio frequency (RF) signal to be able to properly optimize system performance. The measurement of received signal strength is referred to as a received signal strength indicator (RSSI), and may be developed in either the analog or the digital domain. The generation of a RSSI value using analog circuitry is the more frequently used approach, due to its ability to represent a wider dynamic range in fewer bits of information. The operation of the analog signal processing circuitry in such devices, however, is significantly affected by a number of factors including, for example, variations in power supply voltages, changes in operating temperature, and the processes by which the devices in the circuitry were fabricated. These factors are referred to as process, voltage, and temperature (PVT) variations. Errors in the receive signal strength indication that result from PVT variations may cause the receiver in a wireless LAN to malfunction, or to perform in a sub-optimal fashion. This may result in reduced operating range and/or unacceptable data error rates.
In order to reduce the effects of PVT variations, designers of RF communication equipment such as, for example, wireless LAN systems may incorporate compensating functionality into the analog portions of the receiver design, in an attempt to make the receiver less sensitive to PVT variations. Implementing this compensating functionality typically involves additional circuit components that require resources such as additional area in integrated circuit devices, and additional power for operation. The resources needed to meet the increasingly stringent requirements of advancing wireless LAN standards may raise the complexity of the required integrated circuits to a point where a design using analog compensating functionality is rendered too complex or too expensive for the intended application.
Further limitations and disadvantages of conventional and traditional approaches will become apparent to one of ordinary skill in the art through comparison of such systems with the present invention as set forth in the remainder of the present application with reference to the drawings.